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(19) 




EuropSlsches Patentamt 
European Patent Office 
Office europ6en des brevets 







(11) 



EP0 741 177 A2 



(12) 



EUROPEAN PATENT APPLICATION 



(43) Date of publication: 

06.11.1996 Bulletin 1996/45 

(21) Application number: 96105289.1 

(22) Date of filing: 02.04.1996 



(84) Designated Contracting States: 
BE DE FR GB IT LU NL SE 

(30) Priority: 03.05.1995 US 433285 

(71) Applicant: National Starch and Chemical 
Investment 
Holding Corporation 
Wilmington, Delaware 19809 (US) 



(51) IntCl. 6 : C09J 11/06 



(72) Inventors: 

• Sharak, Matthew L 

Franklin Park, New Jersey 08823 (US) 

• Paul, Charles W. 

Madison, New Jersey 07940 (US) 

(74) Representative: Hagemann, Heinrich, Dr.rer.nat, 
Dipl.-Chem. et al 
Patentanwdlte 
Hagemann & Kehl 
Postfach 86 03 29 
81630 MOnchen (DE) 



(54) 



Sucrose Benzoate as a tackif ier for water sensitive or biodegradable hot melt adhesives 



(57) Hot melt adhesive compositions are prepared 
from a water sensitive or biodegradeable thermoplastic 
adhesive polymer using sucrose benzoate as a tackif ier. 
More particularly hot melt adhesive compositions are 
prepared from 10 to 90% by weight of a biodegradable 
or water sensitive thermoplastic polymer, 5 to 80% by 
weight sucrose benzoate, 0 to 80% by weight plasticiz- 
ing diluent, 0 to 50% by weight wax and 0 to 3% by 
weight antioxidant. 



CL 

LU 



EP0 741 177 A2 



Description 

Hot mett adhesives are used commercially for a wide variety of applications. The major advantage of hot melt adhe- 
sive systems is the lack of a carrier fluid which eliminates the need for drying the adhesive film once it is applied to the 
substrate. This elimination of the drying step overcomes hazards associated with solvent usage and also allows for 
faster production line speeds and lower transportation costs. Depending on the desired use, the degree of tack of the 
hot melt adhesive may be tailored over a wide range to produce adhesives varying from pressure sensitive to non-pres- 
sure sensitive in character. Non-pressure sensitives are used, for example, in bookbinding, bag ending, case and car- 
ton sealing. Pressure sensitive hot melts are used in many applications, and particularly in disposables such as diapers, 
sanitary products and the like, where room temperature tack and long open time are often required. 

Hot melt adhesives have historically been based on petroleum derived polymers such as polyethylene, ethylene- 
vinyi acetate, styreneic block copolymers, and polypropylene to name a few. These compositions are further tackified, 
plasticized and reinforced with a variety of resins, oils and waxes which are also derived from both petroleum and nat- 
urally occurring feedstocks. These classic compositions suffer from the cyclical price cycles common to all oil derived 
materials, and also are generally very resistant to degradation once the articles employing them are disposed of. 

The recent growing movement away from petroleum derived raw materials to those derived from renewable, natural 
resources has led to the use of new water sensitive, biodegradable and/or compostable polymers as the base polymers 
in hot mett adhesive compositions. Thus, water sensitive and/or degradable adhesive compositions have been pro- 
posed containing such raw materials as hydroxybutyrate/hydroxy-valerate polymers, polytactide homo- or copolymers, 
hydroxypropyl cellulose, cellulose acetate, starch acetate, hydroxy functional polyesters and the tike. While the resultant 
adhesives may be improved with respect to their water sensitivity and/or degradability, the overall water sensitivity 
and/or degradability of the adhesive has been retarded by the presence of other additives, such as tackif iers and plas- 
ticizers conventionally used in adhesive compositions. In particular, due to the polar nature of the water sensitive or bio- 
degradable polymer, finding a compatible tackif ier, but also degradable has been difficult. 

There is thus a need for a tackifying material which will not only be degradable in itself but which will also be com- 
patible with a wide range of the above-described adhesive polymer bases. 

SUMMARY OF THE INVENTION 

We have now found that sucrose benzoate is compatible with and provides adequate tackifying properties to a wide 
range of biodegradable and/or water sensitive polymers. Thus, the present invention is directed to improved hot melt 
adhesive compositions comprising a water sensitive or biodegradeable thermoplastic adhesive polymer, and a tackif ier, 
optionally additionally containing a compatible plasticizer, wax and/or stabilizer; the improvement which comprises 
using sucrose benzoate as the tackif ier. ! — — 

More specifically, the present invention is directed to water sensitive and/or biodegradable hot melt adhesive com- 
positions comprising 10 to 90% by weight of a biodegradable or water sensitive thermoplastic polymer, 5 to 80% by 
weight sucrose benzoate, 0 to 80% by weight plasticizing diluent, 0 to 50% by weight wax and 0 to 3% by weight anti- 
oxidant. 

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 

Suitable water sensitive and/or biodegradable thermoplastic polymers for use as the base polymer in the hot melt 
adhesive compositions include, for example, hydroxybutyrate/hydroxyvalerate polymers, polylactide homo- or copoly- 
mers, hydroxypropyl cellulose, hydroxy functional or a liphatic polyester s, starch esters or cellulose esters having a 
degree of substitution (DS) less than 2.5 and the like. — — 

Useful polymers therefore include homo- or copolymer of polylactide containing at least 20 molar percent of the lac- 
tide comonomer. The general structure of the polylactide is shown below: 




suitable polymers for use herein have a number average molecular weight (M,,) within the range of 10,000 to 200,000. 



EP0 741 177 A2 



10 



15 



While poly(D,L-lactide) and the meso- a re essentially amorphous, poly(L-lactid e) or poly(D-lactide) are crystalline 
in nature and h^a'CTystellinenTelting point of 186"C depending on moieculaFwfeight and stereopurity. The polymers 
may be prepared by ring-opening polymerization of the bimolecular cyclic ester of lactic acid with acid or base catalysts 
such as PbO, SnCI 2 , SnCI 4 , ZnCI 2 . SbF 5( Sb^. or triethylamine using solution, precipitation or melt processes. Alter- 
natively, they may be obtained commercially from Henley Chemicals, Inc. under the Resomere tradename; from poly 
Sciences Inc. or from Ecological Chemical Products Company (Ecochem). - - — N - 

In addition to homopolymers of poly(l-lactide). p^OUicWey, and pdy(meso-lactae) suitable polymers for use 
herein may also be prepared by copolymerizationwifii other lactones suarsTgfySside or caprolactone. Thus, 
poly(D,L-iatftf e-co-glycoside) polymers containing equimolar amounts of the lactide and glycoside components are 
available from Henley Chemicals as Resomer RG502. 503, 504, 505 and 506 and are suitable for use herein. In addi- 
tion, poly(D.L-iactide-co-glycoside) polymers known as Resomer RG752, 755 and 756 containing 75% of the lactide 
component as well as the Resomer 858 polymer which contains 85% lactide are also suitable. 

The use of this class of polymer in hot melt adhesives is described in U.S. Patent Nos. 5,252,646 and 5,312,850 to 

lovine et al. 

Also useful herein are the linear polyesters of 3-hydroxybutyric (HB) and 3-hydroxyvaleric (HV) acids produced 
from the fermentation of sugars by the bacterium Alcaligenes eutrophus. The general structure is shown below: 



20 



25 




CH 3 

o hih 

^CHf V, 



O CH, 



Jl 

X 



30 



35 



HYDROXYVALERATE (HV) 



HYDROXYBUTYRATE (HB) 



Polymers suitable for use herein contain 9 to 35% of the hydroxyvalerate component and are available from Zeneca 
under the Biopol tradename. 

The use of these polymers in hot melt adhesive is described in U.S. Patent No. 5,169,889 to Brady et al. 

Also useful are the thermoplastic methylol polyesters containing repeating units of the formula: 



40 





O O CHiOK 



45 



50 



55 



wherein each of R 1 and R 2 is individually a divalent organic moiety which is predominantly hydrocarbon, each R 3 is indi- 
vidually hydrogen or lower alkyl, y is a fraction from 0 to 0.5 and x is a fraction from about 0.05 to about 0.4. 

These hydroxy functional polyesters are suitably prepared by contacting one or more diglycidyl ethers or diglycidyl 
esters with one or more diacids or anhydrides under conditions including the use of an onium catalyst sufficient to cause 
the acid moieties to react with epoxy moieties to form a polymer backbone having ester linkages and pendant methylol 
moi eties. Depending upon the particular starting materials, the resulting polymer will be crystalline, semi-crystalline or 
imor^housjn nature. 

iepreparation of these materials are described in greater detail in US. Patent No. 5.1 71 ,820 to Mang et al. while 
their use in hot melt adhesives is described in co-pending application Serial No. 08/433.578, filed on May 3, 1995 here- 
with. 

Aliphatic polyesters are derived from aliphatic diacids and diols. These also vary in cr ystallintty from amorphousto 
highly crystalline. They are available from HOIs under the Dynapol tradename. ~ 

The use of hydraxypropyl cellulose in hydrophilic hot melt adhesives has been disclosed, for example, inUS. Pat- 
ent 5,356,963 issued October 18, 1994. Similarly, cellulose or starch esters, especially cellulose acetate and starch 



EP0 741 177 A2 




acetatejiavinga degree of substitution less than 2.5 may also be tackified with sucrose benzoate in accordance with 

^^^rnb^M^ *"* eSterS 1101 melt h3S b6en diSC,0Sed in ' amo "9 U S. 5.360.845 

Depending on the base polymer, various grades of sucrose benzoate may be employed as the tackrfier For our- 
posesherem we have found.that the alcohol soluble partially esterified grade of sucrose benzoate is the most generally 
compatible. This grade is a light colored, clear noncrystalline s olid with a softenin g poirrtoLabout 95'C For some base 
polymers, it is also possible to use the non-alcotoTol^ic^oTuble grade whi* is substertW^ esterified and is 
water-dear non^c^y^ ^ noted ^ grade j s ^ 

Ln E^??" ^/T beCaUS t! ^ Unre8Cted ****** Srades are available commerciaiiy 

Lmk from Velacol Chemical Corporation. The amount of sucrose benzoate required will depend upon the other components 
in the adhesive as well as upon the desired end properties; however, it is usually present in an amount of 5 to 80% bv 
weight, preferably 20 to 60% by weight. "moum or o to eu% Dy 

/und2!l! ^ t P ST ntS r ; C0 I 1Venti0nally UtHi2ed in h0t m6lt adhesive ""PWltkw may also be used herein. It will be 
f understood that the particular components used will vary depending upon the intended end use of the adhesive as well 

V 75 Ca T UH l.i *• ?»» " Bh *• *e™P«a«ic polymer errployed. ft wiH a'.so be r^TZZ rr^ 

t water sensitive or biodegradable the additive used, the more degradable will be the resultant adhesive 

«J22 ( 2!r ^ 8 ^ JPP |iC8tion - 80(1 Particularly for uses requiring pressure sensitive properties, various 

ZSSSES^Z ? °5 ^ 8180 be "T in *• J"*™? plastidze* 

1 , " cl " de P*" 8 ' 8 * 8 Plashcaers such as dioctyl phthalate: l.^ujd polyesters such as3^aco^0> om Huls benzoate 

*-LS2^h ,U * d S hy,e ?K 9 ' y< ?' dib6nZOate (- *' ^^SO-available comme ^ally tJ^&fsSSSS- 
S ^£T£ m °' e ,raCti ° n 01 which have been esterified ranges from 0.5 to 0 95 

fS Be ^r^S° h Hydr0Xy from Veteico1 ) : P^^ 8 P" 88 ^ such as t-butylphenyl diphenyl phosphate (If 

n^S SSSTTS? * o° m M0nSant ° ): P"***™ and^tives thereof suc^stephe^ 
nyl ether of ^(ethylene glycol) (e.g.. Pycal 94 available commercially from ICI) as well as liquid rosin derivatives haT- 
2s ,ng Ring and Ball melting points be«Wc such as the methyl ester oi hydrogenat« «EJ5 TSSTd 

EiJEES ? h ^ 5 V69etaWe 8nd animal * Such 88 esters of fat^aSs and polymerization pTTc£ 

hereof. If used, the plasterer is generally present in amounts up to about 80% by weight, preferably 10-to 40%^ 

™ ™ ^ apjirations conventionally employing adhesives based on these water sensitive or btodegrada^lymers 
so wjrwMrt the use of wax diluents in order to reduce the melt viscosity or cohesive characteristics offteCTeTt 
adhesive composrtions wrthout appreciably decreasing their adhesive bonding characteristics Thesfwaxe "are often 

T^r" £** T T M P ~* pr °P ertes - ■ P«St the waxes Se^Sina^ J to 

about 50% by weight, preferably 5 to 35% by weight. ^ 

Suitable waxes include N-(2-hydroxyethv0-12-hydroxy stearamide wax. hydrogenated castor oil. oxidized synthetic 
35 waxes, polyethylene oxide) having a weight average molecular weight above about 1000 ano^nctiSSSd Shetic 
waxes such as carbonyl containing Escomer H101 from Exxon Tunci.onai.zed synthetic 

conlS^^r^ ** "*T" formulations describ «J "erein may contain both wax and plasticizer 
components so that the presence of one or the other is not mutually exclusive 

riho ^r n L the a " >liCable s * abilizere w antioxidants which may be included herein are high molecular weight hindered 
40 phenote and mutWu.Kt.onal phenols such as sulfur and phosphorous-containing phenols. Representee h nde ed 

r^^^ ^^oP-onate; n-octadecyl 3.5<li-tert*utyl^hydroxyphenyl) propionate; 4.4'-methy lenebis 
^h^lr?? 8 " 0 ^ 4,4 '"^ 8 ^-^-o-cresol); 2.Mi-tert-burytohVnd; 6-(4*y*^^ 

^t 88 may 68 incorporated into the hot melt compositions in order to modify certain properties thereof 
Among these additives may be included colorants such as titanium dioxide; and fillers such as talc and day rtc ThSe 
may also be present .n the adhesive small amounts (e.g., less than about 20% by weight and prefe^lv S to 20% £ 

50 S?fiS ih t the r P,aStiC and/ ° r P ° ,ymere 68 are conventiona'y^S,^ SSS - iSSS? 

impart flex* lity. toughness, strength andtor water sensHivity. Suitable thermoplastic polymers include ethylene tJnS 
acetate, ethylene acryiic acid, ethylene methyl acrylate and ethylene n-butyl aaylate ccXm^s cor^n^P to S 
viny. or acrytete monomers. Suitable hydrophilic polymers inc.Se polyv^alcohThy^Z ^SSXSSSS 
pyl cejulose. polyvinyl methyl ether, polyethylene oxide). polyvinyipSone and the Z hydroxypro- 

n.rJ^l I™* adh8SiVe COmp ° Sitions be fo^uteted using techniques known in the art. An exemplary proce- 
ISSF ^ aan9 ! PP ™ C,mately 40%ofthetotel *ackJfying resin concentration with all the polymer^ mSSL 

S 8 range of from up to about 1 90-C. After the resin has mSed 'the^Sure fe 

lowered to 150 to 165'C. M.x.ng and heating are continued until a smooth, homogeneous mass is obtained whereupon 



EP0741 177A2 

the remainder of the tackifying resin is thoroughly and uniformly admixed therewith. The adhesives disclosed her in 
may be employed in a wide variety of uses as are known in the art The adhesives described herein may be effectively 
utilized in a variety of packaging and carton sealing applications. The non-pressure sensitive adhesives may also be 
used to bind a plurality of sheets in a wide range of bookbinding operations. They may also be used for laminating tissue 

5 and/or screen-reinforced tissue layers such as are used in individual or roll use applications as in wTpersrpaper towels r 
toilet tissue and other consumer or industrial end uses. When formul ated with plasticizer s, the resultant adhesives may 
be used in the assembly or construction of various disposable articles including, but not limited to sanitar y napkins, dis- 
posable diapers, hos pital gowns, bed pad s a nd the like. In particular, adhesives are useful for the assembly of dispos- 
able articles using spray orTnulPine construction techniques wherein at least one flexible film substrate is bonded to 

10 at least one tissue, non- woven, polyolefin or other flexible polymeric film substrate. In addition, the adhesives may be 
useful in the bonding ofelastc to polyethylene, polypropylene or non-woven substrate so as, for example, to impart 
elongation resistant gathers thereto. The adhesive may also be utilized in less demanding disposable construction 
applications such as for end or perimeter seating. 

In the following illustrative examples all parts are given by weight and all temperatures in degrees Celsius unless 
is otherwise noted. 

EXAMPLE I 

This example shows the preparation of a hot melt adhesive with completely biodegradable components. Here the 
20 base polymer is polylactide, which can be formulated with either the regular or ASG grade of sucrose benzoate. 





A 


B 


Polylactide 


30 


30 


Sucrose Benzoate (ASG) 


40 




Sucrose Benzoate Regular 




40 


Crtrof lex 2 


30 


30 


Irganox 1010 


0.5 


0.5 


Crtrof lex 2: Triethyt citrate from Morf lex Irganox 
1010 is a hindered phenol antioxidant 



35 The above examples are clear, pressure sensitive with excellent mechanical properties. 
EXAMPLE II 

This shows how another biodegradable hot mett adhesive can be made based on hydroxybutyrate/valerate 
40 (PHV/B), with other biodegradable components. PHV/B is available from Zeneca under the tradename Biopol. 





C 


Biopol 


40 


Sucrose Benzoate (ASG) 


40 


Surfbnic DNP-100 


20 


Irganox 1010 


0.5 


Surfonic DNP 100 Dinonyl phenol 
10 mole ethylene oxide from 
Huntsmen 



Example C is an opaque non-pressure sensitive hot mett with good compatibility. 

55 

EXAMPLE HI 



This experiment shows how hydroxypropyi cellulose, Klucel, available from Aqualon in varying molecular weight 
ranges can be made into a water sensitive/dispersabie hot melt adhesive with the alcohol soluble grade of sucrose ben- 



i 



EP0 741 177 A2 

zoate as the tackHier. 





D 


KlucelL 


15 


Sucrose Benzoate (ASG) 


50 


Pycal94 


20 


Heroolyn D 


15 


Irganox 1010 


0.5 


Pycal 94 is an ethoxylated phenol with 
approximately 4 moles of ethyleneox- 
ide, available from 1CI Specialty Chem- 
icals. 

Hercolyn D is the methyl ester of rosin, 
available from Hercules. 



20 The above example adhesive was clear, water sensitive, with excellent mechanical properties and stability. 
Other grades of Wucel, varying in molecular weight as follows may also be used: 



Type 


MW* 


H 


1,150,000 


M 


850,000 


G 


370,000 


J 


140.000 


L 


95,000 


E 


80,000 



'Weight average 
molecular weight 

35 determined by size 

exclusion chromato- 
graph. 

The preferred grades for use herein are E, L and J. 

40 

EXAMPLE IV 

This shows how a water sensitive and biodegradable polymer, starch acetate can be made into a hot melt adhesive 
with the alcohol soluble grade of sucrose benzoate. In this sample, the viscosity was measured using a BrooWield vis* 
45 cometer (Spindle 27) at various temperatures as noted. 



so 



55 



EP0 741 177 A2 





E 


Starch Acetate, DS = 1.6* 


45 


Macol 206EM 


45 


Sucrose Benzoate (ASG) 


10 


Sarttovar A 


0.5 


TNPP 


0.5 


Viscosity (cp) 




250°F 


5,238 


275°F 


2.670 1 


300°F 


1.635 


325°F 


1,195 


350°F 


845 


Macol 206EM 6 mote ethoxylate of 
Bisphenol A from PPG 
Santovar A is a hindered phenol available 
from Monsanto 



* D.S. - degree of substitution per glucose 
repeat unit, with 3 being full acetylation 



EXAMPLE V 

In the following exarrple various grades of methylol poly(ether, esters) available from Dew Chemical were evalu- 
ated with the alcohol soluble grade of sucrose benzoate. In preparing the following samples, a heavy duty mixer which 
had been heated to 165°C and which was equipped with a stirring paddle was charged with 40% of the tackifying resin 
and/or diluent. After melting of the resins, stirring was then initiated whereupon the polyester was added slowly at 
165°C over a one-half hour period after which the temperature was lowered to 150°C. Heating and stirring were contin- 
ued until a homogeneous mass was obtained whereupon the remainder of the tacWfying resin and/or diluent was 
admixed therewith. 

The samples were tested using the following procedures: 

Viscosity measurements were determined after 30 minutes using a Brookfield viscometer (Spindle 27) at 250°E 

The adhesive was also subjected to Peel/Shear testing such as is conventionally required in the packaging industry. 
Peel Temperature Test: A bead of test adhesive approximately 1/8 inch in diameter is applied at 325°F to 350°F with a 
glass rod onto 60 pound/ream kraft paper. A second sheet of the same paper is superimposed on the first sheet within 
2 seconds and pressed thereto to form a kraft-to-kraft bond. The bonded sheets are then cut perpendicular to the adhe- 
sive line into 1 inch wide strips. Duplicate bonded specimens are placed in an oven with one free end of the specimen 
attached to a fixed support and a 100 gram load suspended from the other sheet at the same end of the bond. The oven 
temperature is then increased in 10°F increments at 15 minute intervals. The temperature at which bond delamination 
occurred is specified as the peel temperature. 

Shear Temperature Test: Samples are prepared as in peel temperature test but separate sheets of Kraft at opposite 
ends of the bonded specimen are suspended and weighted to stress the bond in a shear mode. The temperature of the 
oven is increased as in peel test until failure occurs. 

Adhesion Test: A molten bead of hot melt at 325°F to 350°F was drawn across the middle (widthwise) of a r x 3" 
strip of corrugated paper. A second strip of corrugated paper was then immediately superimposed upon the first and a 
50 gram weight placed on top of the construction. The kraft-to-kraft bonds were then aged 24 hours at room tempera- 
ture. After aging, the samples were stressed by hand at the temperature noted (0°F t 20°F or 40°F) in a 90° peel mode. 
The presence of f ber tear indicates excellent adhesion. 

Tack and Range were measured by drawing out a 3 mil thick adhesive film and qualitatively measuring the tack by 
determining how many successive finger prints could be made in the film before it set The range or open time indicates 
the number of seconds during which the finger prints can be made. Cigarette plug adhesion was measured by applying 



EP0741 177 A2 



a bead of adhesive to cigarette plug paper, forming a bond and conditioning the bond for 24 hours at room temperature. 
After conditioning, the bonds were pulled at 180° mode by hand. 

Some of the adhesives were also tested for t hermal stab ility by storing at 275°F for 24 hours and then noting the 
appearance of the adhesive. v -^=~^ — - 

""" ^"Samples J and K are typical formulations used in non-pressure sensitive packaging case and carton seal type 
application. In these samples, the crystalline poly(ether t ester) formed from the reaction of hydroquinone diglyctdyl 
ether with 1 , 1 O-decandicarboxyiic acid was employed (CRY). These formulations have low viscosity and good high tem- 
perature performance as can be seen from the good peel/shear values. Also, the products have good lo w temper ature 
performance as is demonstrated by the good adhesion to corrugated at low temperatures. Lastly, these products"fiave 
excellent adhesion to cigarette plug wrap. 





F 


G 


CRY 


50 


50 


Sucrose Benzoate ASG 




20 


Benzoflex 2-45 High Hydroxyl 


30 


10 


Paracin 220 


20 


20 


Irganox 1010 


0.5 


0.5 


Viscosity (cp) @ 250°F 


5,612 


10,920 


Peel (F) 


100 


110 


Shear (F) 


180 


180 


Tack 


Slightly Aggressive 


Aggressive 


Range 


3 seconds 


4 seconds 


Corrugated Adhesion 






0°F 


50% 


80% 


20°F 


70% 


85% 


40°F 


70% 


85% 


Cigarette Plug Wrap Adhesion 


Excellent 


Excellent 


Benzoflex 2-45 High Hydroxyl - diethylene glycol benzoate where about 0.75 mole 
fraction of hydroxyl groups have been esterified to benzoate esters from Velsicol 
Chemical Corporation. 



The test results presented above show the adhesives to be particularly suitable for packaging applications such as 
case and carton sealing due to its low viscosity, good ffoer tear and acceptable peel and shear values. 

Another series of hot melt adhesives were formulated into pressure sensitive formulations using an essentially 
amorphous poly(ether, ester) derived from the reaction of bisphenol A diglyckJyl ether and 1 ,4-cydohexanedicarboxylic 

acid~(AMP)7"' - 



EP0741 177 A2 

The compositions and test results are shown in the tables which follow: 





H 


AMP 


25 


Sucrose Benzoate ASG 


40 


Benzof lex 2-45 High Hydroxyl 


35 


Irganox 1010 


0.5 


Comments 


Good compatibility 


Viscosity (cp) 




@ 275°F 


4115 


@300°F 


2250 



The resultant adhesive was evaluated and found to give a clear water white product. Poly/non-woven bonds were 
20 made by heating the adhesive to approximate ly^! 35° C and apply ing a thin-bead of adhesive onto the polyethylene and 
quickly mating the non-woven and next applying compression with a 200~g*"weight or rolling over the bond with a 5 lb. 
roller. The bonds were then pulled by hand and gave deformation of the substrate which indicated good penetration and 
good adhesion properties. 

In the following formulations several waxes were used in the adhesive formulations in conjunction with the 
25 poly( ether, ester) and the sucrose benzoate. 



55 



EP0 741 177 A2 







1 
i 


i 

j 




t 

L 


5 


AMP. 


on 


on 


on 


on 




OUCrOSG DGnZOole 


An 


Aft 


An 


An 




Castor wax 


lu 










rvemamiue w-*hj 




lO 






in 


raracin 2^u 






10 






D JT_JJ1_ JlUjlU 

benzotiex ou 








or 




oenzoriex 2-45 mgn nyaroxyi 


on 
30 


oc 
25 


do 




15 


irganox ioio 


n c 

0.5 


n c 

0.5 


U.O 


n r 




comments 


compatible 


compatible 


uompduuie 


compatiuie 




viscosity (cp) 












© 250 r 






2,455 


not testeo 


20 


<§> 275 r 


1,340 


^ inn 

4,100 


1,290 






(g> 300 r 


TOE 

735 


1,420 


715 






uorrugateo Aanesion 










25 


ADC 

Or 


* ac/ 
10% 


not testeo 


ncv 
U% 


0% 




20 r 


20% 




0 


0 




40° F 


ACQ/ 

95% 




4 a 

10 


10 




Peel (°F) 


4 AA 

100 




•* OA 

130 


140 


30 


Shear <°F) 


100 




170 


170 




Tack 


Aggressive 


Very Aggressive 


Very Aggressive 


Very Aggressive 




Range (seconds) 


8 


1 


5 


2 


35 


Castor Wax, Cas Chem: Hydrogenated castor oil 
Kemamide W40, Witco: N.N'-ethyienebisstearamide 



40 As the results indicate, all of the waxes evaluated were compatible in the formulations. In Samples I, J, K and L the 
low temperature performance was not within acceptable levels; however, the high temperature performance was within 
acceptable levels suitable for pressure sensitive type applications, such as in the construction of disposable articles 
where low temperature performance is not critical. 

45 Claims 

1 . A hot melt adhesive composition comprising 10 to 90% by weight of a biodegradable thermoplastic adhesive poly- 
mer selected from the group consisting of hydroxybutyrate/hydroxyvalerate polymers, poiylactide homo- or copoly- 
mers, hydroxypropyl cellulose, cellulose or starch esters having a degree of substitution less than 2.5, hydroxy 

so functional or aliphatic polyesters; 5 to 80% by weight sucrose benzoate, 0 to 80% by weight of a plasticizing diluent 
selected from the group consisting of phthalate plasticizers, liquid plasticizers, benzoate plasticizers, phosphate 
plastidzers, poly(ethyiene glycols) and derivatives thereof; liquid rosin derivatives having Ring and Ball melting 
points below about 60«C, vegetable and animal oils and the polymerization products thereof; 0 to 50% by weight of 
a wax selected from the group consisting of N-(2-hydroxy -ethyl)* 12 -hydroxy stearamide, hydrogenated castor oil, 

55 oxidized synthetic waxes, polyethylene oxide) having a weight average molecular weight above about 1000 and 
functionalized synthetic waxes, and 0 to 3% by weight antioxidant 

2. The hot melt adhesive of Claim 1 wherein the water sensitive or biodegradable polymer is a homo- or copolymer of 
poiylactide containing at least 20 molar percent of the lactide comonomer. 



EP 0 741 177 A2 

3. The hot melt adhesive of Claim 1 wherein the water sensitive or biodegradable polymer is a linear polyester of 3- 
hydroxybutyric and 3-hydroxyvaleric acid. 

4. The hot melt adhesive of Claim 1 wherein the water sensitive or biodegradable polymer is a thermoplastic methylol 
5 polyester prepared by the reaction of one or more diglyckJyl ethers or diglycidyl esters with one or more diacids or 

anhydrides. 

5. The hot melt adhesive of Claim 1 wherein the water sensitive or biodegradable polymer is hydroxypropyl cellulose. 

w 6. The hot melt adhesive of Claim 1 wherein the water sensitive or biodegradable polymer is starch acetate having a 
degree of substitution less than 2.5. 

7. The hot melt adhesive of Claim 1 wherein the water sensitive or biodegradable polymer is an aliphatic polyester. 
is 8. The hot melt adhesive of Claim 1 wherein the sucrose benzoate is present in an amount of 1 0 to 40% by weight. 
9. The hot melt adhesive of Claim 1 wherein the sucrose benzoate is partially esterif ied. 



20 



25 



30 



35 



40 



45 



50 



55 



(19) 







(12) 



Europfiisches Patentamt 
European Patent Office 
Office europeen ties brevets (11) EP 0 741 177 A3 

EUROPEAN PATENT APPLICATION 



(88) 


Date of publication A3: 


(51) Int. Cl. 6 : C09J 11/06 




19.03.1997 Bulletin 1997/12 


(43) 


Date of publication A2: 






06.11.1996 Bulletin 1996/45 




(21) 


Application number: 96105289.1 




(22) 


Date of filing: 02.04.1996 




(84) 


Designated Contracting States: 


(72) Inventors: 




BE DE FR GB IT LU NL SE 


• Sharak, Matthew L 






Franklin Park, New Jersey 08823 (US) 


(30) 


Priority: 03.05.1995 US 433285 


• Paul, Charles W. 


(71) 


Applicant: National Starch and Chemical 


Madison, New Jersey 07940 (US) 




Investment 


(74) Representative: Hagemann, Helnrich, Dr.rer.nat, 




Holding Corporation 


Dipl.-Chem. et at 




Wilmington, Delaware 19809 (US) 


Patentanwdtte 






Hagemann & Kehl 






Postfach 86 03 29 






81630 MOnchen (DE) 



(54) Sucrose Benzoate as a tackHier for water sensitive or biodegradable hot melt adhesives 

(57) Hot melt adhesive compositions are prepared 
from a water sensitive or biodegradeable thermoplastic 
adhesive polymer using sucrose benzoate as a tackif ier. 
More particularly, hot melt adhesive compositions are 
prepared from 10 to 90% by weight of a biodegradable 
or water sensitive thermoplastic polymer, 5 to 80% by 
weight sucrose benzoate, 0 to 80% by weight plasticiz- 
ing diluent, 0 to 50% by weight wax and 0 to 3% by 
weight antioxidant. 



EP0 741 177 A3 




European Patent 
Office 



EUROPEAN SEARCH REPORT 



Application Noatber 

EP 96 1G 5289 



DOCUMENTS CONSIDERED TO BE RELEVANT 



Category 



Citation of document 
of 



Appropriate, 



to data 



CLASSIFICATION OF THE 
APPLICATION (lotCLo) 



DE 14 68 736 A (VELSICOL CHEMICAL CORP. ) 

* page 7 f line 5 - line 14 * 



1 



C09J11/06 



TECHNICAL FIELDS 
SEARCHED (latCLa) 



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CATEGORY OF CITED DOCUMENTS 



X : particalarly relevant If take* aloat 
Y : particularly relevant If con tie ee with 

eocuaeot of the nat catefory 
A : tocaaoloflcal aackgrouai' 
O : aoa-nrittoa ets desert 
P : latersotlato eoceojeat 



T : theory or prtadplc uaerriyiag the teweatioa 
C : earlier patent Aocuaacnt, bat pafaUsheri on, or 

after to* flliag cat* 
D : aoonaeat dtea la tae application 
L : tfocuaeat dtee for other reasoes 



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